Cannot run the webcam demo

[oschan77]

Hi, I am directly running the webcam demo (https://github.com/open-mmlab/mmaction2/blob/main/demo/README.md#webcam-demo).

~/mmaction2$ python demo/webcam_demo.py demo/demo_configs/tsn_r50_1x1x8_video_infer.py shared/tsn_imagenet-pretrained-r50_8xb32-1x1x3-100e_kinetics400-rgb_20220906-cd10898e.pth tools/data/kinetics/label_map_k400.txt --average-size 1   --threshold 0.2 --device cuda:0

There is no window popping out. It shows the followings, and then it gets stuck:

Loads checkpoint by local backend from path: shared/tsn_imagenet-pretrained-r50_8xb32-1x1x3-100e_kinetics400-rgb_20220906-cd10898e.pth
Press "Esc", "q" or "Q" to exit

How to solve this issue? Is there other way to inference the trained action recognition models in real-time? Thanks!